1. Field of the Invention
This invention relates to an electromagnetically commanded switch comprising a magnetic circuit made up of a main circuit polarised by a permanent magnet and linked to a depolarisation coil and a movable circuit integral with a movable support, subject to a return spring and acting directly or indirectly on at least one disconnecting pole.
2. Discussion of the Background
In order to provide protection for motors against short circuits or overcurrents, thermal relays, motor cut-outs or contact maker/circuit breakers are used.
Through U.S. Pat. No. 5,332,986 or patent application DE 195 14 314, an electromagnetic actuator is known, comprising a magnetic circuit polarized by a permanent magnet and linked to a coil and made up of a fixed part and a movable part, the latter serving as an actuator. In U.S. Pat. No. 53,332,986, the coil is commanded from current sensors and the movable part of the magnetic circuit is integral with an adjusting lever acting on a contact that is ancillary to the power poles.